SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9dd8553f81de9747c23e9877734f141dd122dd9e1f16508ef6b8413d6e3da42d' 
  AND token = 'fwzbpZ48//+eAr/z6kG8QCVwTSulFVRJtgGngfO6tz8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}